package com.example.kirito.util;

/**
 * Created by Kirito on 2016/4/15.
 */
public class Distance
{
    public final double EARTH_RADIUS = 6378137.0;
    public double gps2m(double lat_a, double lng_a, double lat_b, double lng_b) {
          double radLat1 = (lat_a * Math.PI / 180.0);
          double radLat2 = (lat_b * Math.PI / 180.0);
          double a = radLat1 - radLat2;
          double b = (lng_a - lng_b) * Math.PI / 180.0;
          double s = 2 * Math.asin(Math.sqrt(Math.pow(Math.sin(a / 2), 2)
                    + Math.cos(radLat1) * Math.cos(radLat2)
                    * Math.pow(Math.sin(b / 2), 2)));
               s = s * EARTH_RADIUS;
               s = Math.round(s * 10000) / 10000;
               return s;
        }

}
